Question

In developing her science project, Leigh learned that light travels at a constant rateand that it takes 500 seconds for light to travel the 93 million miles from the Sun toEarth. Mars is 142 million miles from the Sun. About how many seconds will it takefor light to travel from the Sun to Mars?A. 235 secondsB. 327 secondsC. 642 secondsD. 763 seconds

Answer 1

D. 763 seconds

Step-by-step explanation:

Data:

Seconds light travels distance between Sun and Earth : 500 seconds

Distance between Sun and Earth: 93 million miles

Distance between Sun and Mars: 142 million miles

Formula: (see image below)

Solution:

From Sun to Mars the light takes (142 * 500) / 93 = 763 seconds

NB:

The tactic is to first put the data given in a table like in the image above, to first multiply diagonally then divide horizontally. (starting from the data that his paired data).

Here the paired data missing is the time it takes for the light to travel from the Sun to Mars, therefore you'll multiply the distance between the Sun to Mars (known data missing a pair) by the time it takes light to travel from the Sun to Earth (known data with its pair), then divide the result by the distance between the Sun and earth (pair of the former mentioned known data)